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                [Ceoi2000] LandsScape                </h1>
                <p>时间限制：10s&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;  空间限制：128MB</p>			</div>
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                                <h3>题目描述</h3><p><div><b><span style="font-size: 16pt">&nbsp;</span></b><span style="font-size: 16pt">话说rins操作技术太无下限了，出门装手一抽就买了2个鞋子，结果没钱了</span><span style="font-size: 16pt">&hellip;</span><span style="font-size: 16pt">于是rins一路被压榨，走上上爆塔，走下下路崩，无奈之下他硬着头皮来到了中路，然后就被pcx虐残了..rins发现自己只有-1滴血</span><span style="font-size: 16pt">,</span><span style="font-size: 16pt">万幸自己无下限</span><span style="font-size: 16pt">..</span><span style="font-size: 16pt">于是掉头就跑，奔到了野区的山岭上，xx紧随其后，带着1000米高精准爆菊神器准备收了这FB。不过此时天色已晚，pcx视力不太好，只有有光的地方才能被他打到，已知天空高度为sky，有t个一闪一闪的小星星位于不同位置，如果<b>山上某一点与星星i的连线不穿过山上其他点</b>或<b>刚好与山整条线重合</b>，则称星星i可以照亮该点，rins开了疾风步，可以躲在任意一点，那么pcx是否能爆了rins，得到fb呢？如果能，则至少要利用几个星星呢？</span></div></p><hr/><h3>输入格式</h3><p><div><span style="font-size: 16pt">&nbsp;</span><span style="font-size: 16pt">第一行</span><span style="font-size: 16pt"> sky</span></div>
<div><span style="font-size: 16pt">第二行</span><span style="font-size: 16pt"> t</span></div>
<div><span style="font-size: 16pt">第</span><span style="font-size: 16pt">3</span><span style="font-size: 16pt">到</span><span style="font-size: 16pt">3+t-1</span><span style="font-size: 16pt">行</span><span style="font-size: 16pt">每行一个数，第</span><span style="font-size: 16pt">i</span><span style="font-size: 16pt">个星星的横坐标，保证星星横坐标已从小到大排好</span></div>
<div><span style="font-size: 16pt">第</span><span style="font-size: 16pt">3+t </span><span style="font-size: 16pt">行</span><span style="font-size: 16pt"> n </span></div>
<div><span style="font-size: 16pt">接下来</span><span style="font-size: 16pt">n</span><span style="font-size: 16pt">行</span><span style="font-size: 16pt">每行两个数，表示山的转折点的<b>纵坐标和横坐标</b></span><span style="font-size: 16pt">，保证横坐标已从小到大排好</span></div>
<p></p></p><hr/><h3>输出格式</h3><p><div><b><span style="font-size: 22pt">&nbsp;</span></b><span style="font-size: 16pt">如果可以虐死</span><span style="font-size: 16pt">rins</span><span style="font-size: 16pt">，则输出最少利用的星星个数；</span></div>
<div><span style="font-size: 16pt">&nbsp;&nbsp; </span><span style="font-size: 16pt">否则输出&ldquo;</span><span style="font-size: 16pt">Shit..I can't see rins...</span><span style="font-size: 16pt">&rdquo;不包括引号。</span></div></p><hr/><h3>样例输入</h3><pre>  100
3
2 7 14
9
10 0
80 3
10 5
70 8
50 10
40 12
20 13
90 14
40 17
</pre><hr/><h3>样例输出</h3><pre> 3
</pre><hr/><h3>提示</h3><p><p></p>
<p></p>
<p><img height="432" width="528" alt="" src="../file/2881_0.jpg" /></p>
<p></p>
<p>数据范围与约定<br />
&nbsp; 对于10%数据 rins RP比较好<br />
对于20%的数据：t=1<br />
&nbsp;对于另外30%的数据：2&lt;=n&lt;=3<br />
对于100%的数据：sky&lt;=10000<br />
t&lt;=100 <br />
2&lt;=n&lt;=100<br />
0&lt;=所有山的纵坐标&lt;sky<br />
0&lt;=所有横坐标&lt;=1000</p></p><hr/><h3>题目来源</h3><p>没有写明来源</p>
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